Elements for use in practice of spirit duplication process



United States Patent ELEMENTS FOR USE IN PRACTICE OF SPIRIT DUPLICATION PROCESS Richard C. Lebl, North Riverside, Joseph Savit, Maywood, and Robert T. Florence, Park Ridge, 11]., assign-- ors to A. B. Dick Company, Niles, Ill., a corporation of Illinois No Drawing. Appllcation Aprll 11, 1956 Serial No. 577,453

15 Claims. (Cl. 101---149.4)

This invention relates to a duplicating process and to elements for use in the practice of same. It relates more particularly to a spirit duplicating process which is free of many of the deficiencies and undesirable characteristics of spirit duplicating processes of the type heretofore employed. I

This is a modification of the invention described in the co-pending application of Klimkowski et al., Serial No. 287,616, filed May 13, 1952, now Patent No. 2,748,024, issued May 29, 1956.

i In the spirit duplicating process of the type heretofore employed, use is made of a water and alcohol soluble dyestuif, such as crystal violet, as a material having color transfer value in the coated carbons and in the imaged master formed thereof. Such water and alcohol soluble dyestuffs having a high color transfer value are responsible in part for the objectionable characteristics of present duplicating systems because the high solubility of the intense dyestutf enables offset on ones hands, and on clothing and equipment coming in contact therewith. The purple dyes-tuft seems to find its way readily onto all surfaces in close proximity with .the manufacture of the carbon sheets or the use thereof in the production of multiple copies. As a result, the purple discoloration appears everywhere and on everything in highly objectionable amounts. The spirit duplicating processes, while being highly flexible and inexpensive processes, are objectionable because of this dirtiness and the necessity to take special precautions for protection.

In the co-pending application of Klimkowski et al., description is made of one-of the first departures from the 2 master imaged with the material containing the diazo compound, with or without the coupler, is subsequently brought into surface contact with copy sheets wetted with a fluid containing a solvent for the diazo and/ or coupler and which also contains a material for pH adjustment to enable coupling reaction to take place .to'form the dyestutf. When the wetted surfaces of the copy sheets are brought into contact with the imaged surfaces of the master sheet, the diazo and coupler are leached for transfer from the imaged master to the copy sheets where reaction takes place in the imaged areas to form the dyestufi. If the master is imaged with a material containing the diazo compound only or a component thereof, the coupler for dye formation can be supplied in the fluid or in the sheets on which the copy is formed.

The diazo and coupler are, in themselves, substantially free of any color transfer value with the result that neither the transfer sheet nor the imaged master are subject to the objectionsof dirtiness which is characteristic of the spirit duplication processes heretofore employed. The elements employed in the practice of the described invention are similar to the elements employed by the present conventional spirit duplication systems with the exception of the freedom of materials having high color transfer value with the result that the described system embodies the fiexibil-i-ties and simplicity characteristic of the present systems for multiple duplication without being subject to the objectionable features thereof.

Where, as in the preferred practice, the diazo com pound alone or in combination with a' coupleris'cont ained in the transfer coating or otherwise in the material with which the master is imaged, copy of acceptable use of a water and alcohol soluble dyestufi in the elements I used to practice the spirit duplicating system. In the aforementioned application, the dirtiness, which characterizes the present spirit duplicating systems, is substantially completely eliminated by the use of a water and alcohol soluble component of a dyestuff having little if any color transfer value in the elements with which the copy is produced. In the described system, the dyestutf is formed of the component or components by reaction upon transfer to the imaged areas of the copy sheet thereby to form the dyestuff after all handling has been completed and thereby to enable a dyestuff to be formed which is substantially insoluble in water.

The process described in the aforementioned copending application finds its best practice in the use of an azo dye system wherein at least one of the water and alcohol soluble components of an azo dyestuif is formulated to be contained in relatively high concentrations in the image on the master sheet or in the transfer coating or other imaging material of which it is formed. Briefly described, the preferred system makes use of a diazo compound, preferably in combination with a coupler in the transfer coating or other material with which the master is imaged. The coated transfer sheet is brought into surface contact with the prepared surface of the master to effect displacement of the transfer coating from the carbon to the master in response to applied force in the imaged areas. The

quality is secured almost immediately, but the number of copies secured is not as great as could be desired. This is believed to be derived from the fact that the diazo compounds used in the imaging material are available in a state wherein the compound is leached immediately and rapidly from the imaging material and out of proportion with the coupler, when present, with the result that insufficient diazo compound remains in the imaging material to produce a large number of copies of acceptable quality.

In the attempt to insure the presence of diazo compound for reaction with the coupler in the imaging material, the diazo-to-coupler ratio was greatly increased by an amount to compensate for the removal of diazo at a greater rate. diazo to coupler, thereby to increase the cost of the sheet and thereby to limit the number of copies by the lesser amount of coupler which could be incorporated. The presence of such excesses of one component with respect to the other in the imaging material and in the dyes-tut of which the copy is formed necessarily leads to a lesser number of copies which can be secured from a single imaged master.

To preserve the diazo compound and increase the coupler ratio in the imaging material and to provide an amount of diazo compound necessary for reaction with the coupler, attempts were made to formulate the imaging material with coupler-stabilized diazo compounds which were less soluble in the fluid with which the copy sheets were wet, and which necessarily provided both diazo and coupler together in the ratio sutficient for reaction to form the corresponding azo dyestuff. While the number of copies available from a master imaged with a system of the type described is markedly increased, copy of acceptable quality did not develop until the machine had been cycled a number of times.

Thus, it is an object of this invention to produce a clean spirit duplicating system of the type described in which copy of acceptable quality can be produced early in the duplicating cycle and in which a large number of copies However, this resulted in a high ratio of of acceptable quality can be secured from a single imaged master.

More specifically, it is an object of this invention to provide :a spirit .cluplicating:system in which use'is made of. an azo dye component substantially free of color transfer value in the material with which the master is imaged but which-embodies acornbination of materials to produce copy of good quality substantially immediately and which makes'more efiicient use of the components present in the imaging material to produce a relatively large number of copies.

These and other objects and advantages of this invention are achieved by the formulation of the imaging material to include a stabilized diazo compound or component thereof and coupler in combination with a conpler-diazo complex compound. The materials can be presentin substantially equal molecular proportions but it is preferred to make use of an amount of the couplerdiazo complex compound considerably in excess of the diazo compound and coupler. In the preferred practice of this invention, the materials are formulated to be present in the ratio of 3 to parts by weight of the diazo compound and coupler to 10 to 60 parts by weight of the coupler-diazo complex compound.

As the diazo compound, use may be made of a diazo dye-forming compound, such as illustrated in theaforementioned copending application Serial No. 287,616, filed May 13, 1952, and preferably the zinc chloride or sulfonic acid salts thereof by which the diazo compound isstabilized to enable storage under widely different atmospheric conditions Without decomposition and which minimizes the possibility of coupling reaction until pH adjustment by the combination with an alkaline substance to bring the pH of the system above 3.5. As stated in the aforementioned application Serial No. 287,616: By maintaining a pH less than 3.5 and preferably as low as 1.5, as by acidification with boric acid, tartaric acid, citric acid and acid salts such as aluminum sulphate or zinc chloride, coupling can be prevented thereby to permit the diazo dye forming component and the coupler to be arranged in the same composition without dye formation but with means for adjusting the pH above 3.5 upon transfer to the copy sheet for coupling to form the colored diazo dyestuff. As stated in the later-referred to application Serial No. 507,739: the diazo compound is stabilized against reaction with the coupler by conversion to a .diazonium salt and/or by adjustment to maintain acidic conditions, as below a pH of 3.5 to prevent coupling. Thus the diazo dye component and the coupler present together in the imaging material are blocked against coupling reaction.

Such compounds are readily soluble in water or in mixtures of water with alcohol and other solvents generally employed in fluid systems used to wet out the surfaces of copy sheets prior to contact with the imaged master.

Instead of making use of a diazo compound of the type described, use can be made of a component of an azo dyestuff which is soluble in alcohol and Water, such as described in the copending application of Klimkowski et al, Serial No. 348,584, filed April 13, 1953, in which use is made of an amine salt and nitrites capable of reaction under acidic conditions to form the diazo compound which then is capable of coupling to form the azo dyestu'tf. The following will represent such intermediate amines as may be used instead of the diazo compounds: M-phenylene diamine hydrochloride, Z-S-diaminotoluene sulfate, 2-4-diaminotoluene p-nitroanaline hydrochloride, benzidine dihydrochloride and the like. The acidic conditions provided to form the diazo reaction operates to stabilize the coating to prevent premature coupling reaction as indicatedin the copending application.

.As the coupler, use may be made of compounds capable of removal of a hydrogen ion for combination with the chloride ion of the diazo compound for dye formation.

.Such .compoundsinclnde the aromatics in the form of amines, such as aniline, and substitute anilines, such as dimethyl aniline, phenolic compounds such as phenol, resorcinol, phloroglucinol, 2,3-dihydroxy naphthalene 6- sulfonic acid, thio compounds such as thiobarbituric acid, and cyano compounds such as cyanoacetamide.

As the coupler-stabilized diazo compounds, use may be made of compounds of the type described in the copending'application of Florence, Serial No. 507,739, filed on May 19, 1955.

These compounds may be prepared by combining an alkaline solution of the sulfonic acid coupler compound with an acid solution of the diazo in which sufiicient free acid is available to more than neutralize the free alkali in the solution of the coupler to form a mixture having a weakly acid pH, preferably within the range of 6.0 to 6.5. By way of example, l-naphthol-8 amino-3,6 disulfonic acid (mono-sodium salt) in alkaline solution is added slowly top-diazo dimethyl aniline to form the corresponding diazo coupler complex of the p-diazo dimethyl aniline salt of 1-naphthol-8 amino-3,6 disulfonic acid. Similarly, other'coupler diazo complex compounds may be formed for use, such as the p-diazo diethyl aniline salt of 2,3 dihydroxy naphthol-6 sulfonic acid, p-diazo diethyl aniline salt of l-naphthol-8 amino-3,6 disulfonic acid, o-anisidine diazo salt of 1-naphthol-6 amino-3 sulfonic acid and the like. As defined in the aforementioned application Serial No. 507,739, the stabilized diazo complex is formed by a non-coupling reaction of the diazo compound with the coupler in acidic medium.

The following will illustrate the practice of this invention.

EXAMPLE 1 Transfer coating composition Compound: Parts by wt. Carnauba wax 14.0 Sperm oil 15.0 Polymerized sperm oil 8.0 Peanut oil 8J0 p-Diazo dimethyl aniline salt of 1-naph thol-8 amino-3,6 disulfonic acid (monosodium solt) 20.0 p-Diazo diethyl aniline zinc chloride 15.0 l-naphthol-S amino-3,6 disulfonic acid (mono sodium salt) 15.0 Titanium dioxide 5.0

EXAMPLE 2 Parts by wt.

PROCEDURE In the preparation of a transfer sheet with the compo sitions described in Examples 1 and 2 above, the materials are combined in a hot melt by heating to a temperature of between -95 C. and the hot melt is coated by conventional means onto the surface of a suitable base sheet preferably treated to provide for a minimum amount of penetration of the coating materials into the paper so that the transfer coating remains concentrated on the surface of the base sheet for ready transfer in response to the application of force. In the preferred practice. the coatings are applied to the base sheet in amounts to provide 10-30 pounds per 3000 square feet of surface area. Instead of the compounds listed above, use may be made of any of the other coupler-stabilized diazo compounds -or diazo compounds or coupler in substitution for the corresponding materials listed in the examples.

1 table oils, fatty acids and the like.

EXAMPLE 3 In the preparation of an imaged master from coated transfer sheets of the types produced by Examples 1 and 2, the coated transfer sheet is positioned with the coated side in surface contact with the prepared surface of a suitable master sheet whereby portions of the coating can be displaced from the transfer sheet to the master in response to the application of force as by means of a stylus, writing pen or pencil, typewriter key, die impression or the like.

f EXAMPLE 4 For the production of multiple copies, the imaged master prepared in accordance with Example 3 is mounted on the cylinder of a rotary duplicating machine.

Prior to bringing the copy sheets into surface contact with the imaged master, the copy sheets are wetted with a fluid formulated to contain the following:

5.0 parts by weight diethanolamine 90.0 parts by weight methanol 5 .0 parts by weight water As the wetted surface of the copy sheets is brought into contacting relation with the imaged master during passage Withthe imaged master between the impression roller and the cylinder, some of the diazo compound coupler and coupler-stabilized diazo compound is dissolved and verted substantiallyimmediately into a dyestuff for the developmentof the copy.

Instead of making use of carnauba wax, sperm oils and peanut oils as the base for the transfer coating, such compositions may be formulated of other waxy materials in various combinations, including carnauba wax,.microcrystalline Wax, ozokerite and the like, alone or in combination with softening agents such as mineral oils, vege- Modification to improve strength and film-forming characteristics may include the addition of small amounts of polyethylene, polybutylene, and other polymeric compounds formed of originally unsaturated aliphatics and other materials capable of compatibility with the waxy substances of the transfer coating.

While it is preferred to apply the transfer coating composition in the form of a hot melt as described in connection with Examples 1 and 2, it is possible to build up the desired coating weights on the base sheet by application of the materials from solvent solution or preferably from aqueous emulsions. Because of the lower solids contents available in such coating systems, more than one coating will usually be required to secure the desired coating weights on the base sheet. 1

In order to produce a large number of copies from, Y

a single coated master, it is desirable to embody as high a concentration of the dye-forming components as possible in the carbon coating composition or in any other material with which the master is imaged consistent with the ability to formulate a coating having the desired continuous film-forming characteristics. Generally, the amount of dye-forming components introduced as an ingredient in the imaging composition depends upon the ability to maintain sufficient fluidity under the conditions of use to achieve the desired application and coverage. For the manufacture of coated carbons, it is desirable to maintain the concentration of the dye-forming components in the imaging material in amounts in excess of by weight thereof and preferably in excess of 50% by weight. However, it is difiicult to formulate a composition that contains more than 80% by weight of'the dye-forming substances. 'Within this concentration, it is desirable to maintainthe components of the dye-forming substances within the ratiodescribed, such as 3-10 parts by weight of the diazo and the coupler to 10-60 parts by weight of the coupler-stabilized diazo compound.

Instead of making use of diethanolamine in the fluid composition for adjustment of the pH, other compounds may be used such as the alcohol and water soluble alkaline substances of the type monoethanolamine, triethanolamine, and other organic amines, ammonium hydroxide or inorganic bases such as sodium hydroxide, potassium hydroxide, and other water soluble hydroxides or salts formed of strong bases and weak acids.

The following will represent other compositions which may be used for producing the image on masters and other fluids-which may be used in combination therewith for wetting the copy sheets to produce copy.

EXAMPLE 5 Compound: Parts by wt. Carnauba wax 8.5 Oxidized microcrystalline wax 14.0 Petrolatum 12.0 Mineral l 15.5 Coupler 3-10 Diazo compound 3-10 Coupler diazo complex 10-60 EXAMPLE 6 Compound: Parts by wt. Carnauba wax 14.0 Sperm oil 13.0 Peanut oil 13.0 6-benzoyl amino-4 methoxyto1uene-3 diazo salt of 1-naphthol-6 amino-3 sulfonic acid 15.0 p-Diazo diethyl aniline zinc chloride 5.0

1-naphthol-8 amino-3,6 disulfonic acid (monosodium salt) 5.0

EXAMPLE 7 Compound: Parts by wt. Carnauba wax 12.5 Microcrystalline wax 10.5 Petrolatum 12.0 Mineral oil 1'5 .0 g p-Diazo diethyl aniline zinc chloride 4.0 1 amino-8-naphthol-4 sulfonic acid 4.0 o-Anisidine diazo salt of 1-naphthol 5 sulfonic acid a 42.0

' EXAMPLE 8 Compound: Parts by wt. Carnauba wax 12.0 Oxidized microcrystalline wax 17.0 Heavy mineral oil 14.5 Light mineral oil 13.0 Sodium oleate 1.5 M-phenylenediamine dihydrochloride 3.0 Phloroglucinol 3.0 p-Diazo diethyl aniline salt of 2,3 dihydroxy 6 sulfonic acid 36.0

The following compositions may be used as fluids:

EXAMPLE 9 12.0 parts by weight diethanolamine 3.0 parts by weight Cellosolve 10.0 parts by weight water 75.0 parts by weight methanol EXAMPLE 10 1.0 parts by weight sodium hydroxide 90.0 parts by weight ethyl alcohol 5 .0 parts by weight methyl alcohol 4.0 parts by weight water EXAMPLE 11 2.0 parts by weight ammonium hydroxide 98.0 parts by weight methanol EXAMPLE 12 "86.0 parts by weight methanol IOLO'parts by weight water "4.0 parts by weight sodium-nitrite The last fluid may be used in combination with a master imaged with the composition of Example8. Where adjustment of the pH on the alkaline side is necessary to effect dye formation, the copy sheets wetted with the fluid of :Example 12 may subsequently be wetted with a second fluid containing the desirable alkaline substances such .as illustrated in Examples 9-11. Thus, there isprovideda two-fluid system such as described in .the aforementioned copending applications.

The components may be distributed in various ways between the imaging material, the fluid, and the copy sheets. For example, one of the essential'components for the formation of the dyestuff may be contained in the copy sheets while the fluid'provides'the m-aterialfor pH adjustment and the imaging material provides the remainder of the components'for dye formation. .In the alternative, two fluids maybe used, one of which'provides one of the components for dye formation While the second fluid provides material for pH adjustment for coupling reaction to produce the dyestuff.

With the system described, in which use is m-ade of a combination of diazo or diazo-forming compound, coupler andcoupler-diazo complex compound, copy can be produced almost immediatelyin the first copy sheet brought into surface contact with the imaged master and the coupler-stabilized diazo complex hasfurther time to become effective for suflicient transfer to the copy sheets in the desired amounts for producing the dyestuif prior to exhaustion of the diazo and coupler, thereby to continue the production of copy of acceptable quality until the coupler-stabilized diazo compound is exhausted. As .a result, the combination described is capable of immediate production of copy and sustained production of copy having good copy quality, thereby to eliminate any deficiencies existing in the azo dye systems used in'spirit duplication.

It will be understood that changes may be madewith respect to the arrangement of the materials and theirconcentrations within the limitations described and their methods of use and application in the copy process without departing from the spirit of the invention, especially as defined in the following claims.

We claim:

1. A transfer sheet for the preparation of an imaged duplicating master comprising a base sheet and a composition, the major proportion of which exists as a coating on the surface of the base sheet to permit substantially complete transfer therefrom, said composition containing a coupler capable of reaction with a diazo compound to form an azo dyestuff, a compound selected from the group consisting of a diazo and an amine capable of diazotization, and a diazo-coupler complex compound, and in which each of the compounds is soluble in a medium selected from the group consisting of alcohol and water and mixtures thereof, said composition being stabilized against coupling reaction to form the azo 'dyestuff at the pH of the coating.

2. A transfer sheet for use inthe manufacture of .an imaged duplicating master comprising a base sheet, a continuous transfer coatingon the base sheet formed of a composition containing a coupler capable of reaction with a diazo compound to form an azo dyestufi, a'diazo and a diazo-coupler complex compound, and in Which each of the compounds is soluble in a medium selected from the group consisting of alcohol and water and mixtures thereof, said composition being stabilized against coupling reaction to form the azo 'dyestutf at the pH of the coating. I

3. A transfer sheet as claimed in claim .lzin'which the materials are present in the transfer coating in the ratio of 3-10 parts by Weight of the coupler, 3-10 parts by weight of the compound selected from the group con- 'sisting of the diazo and amine, and 10-60 parts by weight of the diazo-coupler complex, said composition being stabilized against coupling reaction to form the azo dyestuif at the pH of the coating.

4. A transfer sheet as claimed in claim 1 in which the materials .are present in the transfer coating in an amount to constitute 20-80% by weight thereof. I

5. A transfer sheet as claimed in claim 1 in which the coating is adjusted to a pH below 3.5.

6. An imaged duplicating master comprising a master sheet and an image onthe surface of the master sheet containing a coupler capable of reaction with a diazo compound to form an azo dyestuff, a compound selected from the group consisting of a diazo and an amine capable of diazotization, and a diazo-coupler complex compound, said materials being soluble in a medium selected from the group consisting of alcohol and Water and mixtures thereof, said materials being stabilized against coupling reaction to form the azo dyestufr at the pH of the imaging materials.

7. An imaged duplicating master as claimed in claim 6 in which the materials are present in the ratio of 3-10 parts by Weight of the coupler, 3-10 parts by Weight of the compound selected from the group consisting of the diazo and amine, and 10-60 parts by Weight of the diazocoupler complex, said materials being stabilized against coupling reaction to form the azo dyestuff at the pH of the imaging materials.

8. An imaged duplicating master as claimed in claim 6 inwhich the materials present in the image represent 20-80% by weight thereof.

'9. An imaged duplicating'mastercomprising a master sheet and an image on the master sheet formed of a wax base containing a coupler capable of reaction with a diazo compound to form an azo dyestuff, a diazo compound and a diazo-coupler complex compound, and in which the coupler, the diazo and the diazo-coupler complex are soluble in a medium selected from the group consisting of alcohol and Water and mixtures thereof, said materials being stabilized against coupling reaction to form the azo dyestutf at the pH of the imaging materials.

10. A transfer sheet for the preparation of an imaged duplicating master comprising a base sheet and a continuous transfer coating on the base sheet formed of a wax base containing 2080% by Weight of imaging materials including a coupler, a diazo compound and a diazocoupler complex, each of which is. soluble in a medium selected from the group consisting of alcohol and water and mixtures thereof, said composition being stabilized against coupling reaction to form the azo dyestuff at the pH of the coating.

11. An imaging material containing dye-forming components for use in the preparation of'an imaged duplicating master comprising a carrier containing the dyeforming components including a coupler capable of reaction with a diazo compound to form an azo dyestuff, a compound selected from'the group consisting of a diazo and an amine capable of diazotization and a coupler-diazo complex, each of said compounds being soluble in'a medium selected from the group consisting of alcohol and water and mixtures thereof, said imaging material being stabilized against coupling reaction to form the azo dyestuff at the pH of the imaging material.

12. An imaging material containing dye-forming components for use in the preparation of an imaged duplicating master comprising a carrier containing the dyeforming components including a coupler capable of rebeing stabilized against coupling reaction to form the azo dyestufi at the pH of the imaging material.

13. An imaging material containing dye-forming components for use in the preparation of an imaged duplicating master comprising a carrier containing the dye-forming components including a coupler capable of reaction with a diazo compound to form an 220 dyestutf, a com pound selected from the group consisting of a diazo and an amine capable of diazotization and a diazo-coupler complex compound, each of said materials being soluble in a medium selected from the group consisting of alcohol and water and mixtures thereof and present in amounts to comprise 20-80% by weight of the imaging materials,

said materials being present in the ratio of 3-l0 parts by weight of the coupler, 3-10 parts by Weight of the compound selected from the group consisting of the diazo and amine, and 10-60 parts by weight of the diazocoupler complex, said imaging material being stabilized against coupling reaction to form the azo dyestufi at the pH of the imaging material.

14. An imaging material as claimed in claim 12 in which the carrier is formed of a wax base.

15. An imaging material as claimed in claim 12 in which the material has a pH below 3.5.

No references cited. 

6. AN IMAGED DUPLICATING MASTER COMPRISING A MASTER SHEET AND AN IMAGE ON THE SURFACE OF THE MASTER SHEET CONTAINING A COUPLER CAPABLE OF REACTION WITH A DIAZO COMPOUND TO FORM AN AZO DYESTUFF, A COMPOUND SELECTED FROM THE GROUP CONSISTING OF A DIAZO AND AN AMINE CAPABLE OF DIAZOTIZATION, AND A DIAZO-COUPLER COMPLEX COMPOUND SAID MATERIALS BEING SOLUBLE IN A MEDIUM SELECTED FROM THE GROUP CONSISTING OF ALCOHOL AND WATER AND MIXTURES THEREOF, SAID MATERIALS BEING STABILIZE AGAINST COUPLING REACTION TO FORM THE AZO DYESTUFF AT THE PH OF THE IMAGING MATERIALS. 